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                    MODULE IV: EXCAVATION AND DATING TECHNIQUES
               This  chapter  explores  the  major  methods  of  excavation  and  the  method  of  dating.
           Excavation is a destructive, but most systematic and scientific, documentation of archaeological
           sites. It is a time consuming and expensive field activity. It requires a group of field archaeology
           experts  include  the  director,  co-directors,  trench  supervisors,  trench  assistance,  and  trained
           labours. Sampling experts from different disciplines like Geology, Pedology (the study of soil),
           Petrology (the study of rocks), Paleo-botany, Archaeo-zoology etc is also essential part of a
           scientific  excavation.  Mainly  three  groups  of  method  have  developed  for  the  dating  the
           archaeological material remains like relative, absolute and derivative.
           Excavation
               From the previous chapters we have learned the method of archaeological explorations
           that help the archaeologists to find out the material remains from the surface. Based on the field
           surveys, they will proceed with the trial pits in order to understand the potential of the site.
           Consequently, the archaeologist will start extensive excavation in that area.  Excavation is the
           most systematic and scientific method to retrieve the buried object of the past societies. The
           excavations are  mainly yielding the evidences of two main information on the human past
           societies;  (1)  human  activities  at  a  particular  period  in  the  past  and  (2)  changes  in  those
           activities from period to period. Very broadly, we can say that contemporary activities take
           place horizontally in space; whereas the changes in those activities occur vertically through
           time. It means in an archaeological excavation pit the horizontal space always represent the
           contemporary period and the material evidences collected from the horizontal spaces belongs to
           a  particular  period.  However, after  the  excavation  when  we  observe  all  these  horizontal
           evidences vertically we can see the changes occurred in different period.
           Excavation of mounds
               As we know, the archaeological mounds are the locations that show significant traces of
           human activity, essentially where artifacts, features and eco-facts are found together. It is a site
           where the continuous human occupations occurred in the past.  Two methods are using for the
           excavation of an archaeological site or mount; vertical and horizontal digging.
           Vertical Excavation
               Vertical excavation reveals the total stratigraphy of the site. The sediment layers cut
           perpendicularly and removed the soil in reverse order. Therefore, vertical digging discloses the
           entire cultural deposit of a site. Vertical excavation often starts from the present surface, which
           is known as surface humus layer, and ends at the natural layer, a sediment layer without human
           interaction.
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         Horizontal excavation
             If  the  vertical  digging  exposed  the  cultural  deposits  of  the  past  up  and  down,  the
         horizontal excavation aims to expose the deposits horizontally. It reveals the extension of the
         site while presenting a stratigraphic record in the baulk left between pits. Mortimer Wheeler is
         one of the chief opponents of this excavation by using grid method (see Grid method)
         Open-Area excavation
             This type of excavation aims to expose a large area of the archaeological site without
         maintaining  baulk.  Philip  Barker  is  the  chief  advocate  of  this  method.  This  may  help  the
         archaeologist to realize the total cultural deposit of a site.
         Grid excavation
             Mortimer wheeler has developed the grid system, which is also known as Box-Grid
         System, of excavation to obtain information both horizontally and vertically. He developed the
         grid system of systematic digging whereby the field was divided into small squares. Each square
         clearly separated by a narrow baulk that was never excavated. This method permitted an area to
         be excavated yet preserved a vertical cross-section that revealed the strata of the site as the
         trench was dug. Wheeler's box-grid system has been used universally in modern archaeology
         and although less popular in Europe it is still the most simple method to ensure a systematic
         approach.
         Quartering
             This  is  an  excavation  technique  involving  cutting  archaeological  sites  in  to  four
         quadrants to obtain maximum vertical and horizontal information. It is generally applied to the
         excavation of small mounds.
         Excavation of burials (Quadrant Method)
             Burial excavation leads us to understand various aspects of the human life in the past
         centuries include ritual practices, believes, ancestral belief and belief on life after death. The
         skeletal remains helps to identify the racial affinities, family groups, age, sex, nutrition, palaeo-
         demography, palaeo-diseases and other cultural information. Megaliths are the most important
         burials of Kerala and South India that have archaeological importance. There are different types
         of megalithic burials like Umbrella stone, Cap stone, cist, dolmen, rock-cut sepulchers, stone
         circle, urns, sarcophagus etc.
             Quadrant  method  of is  normally  used  for  the  burial  excavation.  Quadrant  method
         involves dividing the mound or burial into four segments and each quadrant removed very
         systematically. After removing the soil of one quadrant, the archaeologist tries to understand the
         actual position of the burial and then proceed with the removal of remaining three quadrants.
         Even depth must be maintained in the entire quadrant. For instance, if one tries to excavate an
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         urn burial he/she has to remove the four quadrants until the capstone is identified and then
         proceed with removal of one or two quadrant simultaneously. Once the burial is exposed the
         entire  burial  goods  have  to  be  documented  insitu.  The  documentation  includes,  drawing  or
         illustration,  photographs,  mapping  etc.  The  samples,  especially  bones  or  fossils,  charcoal,
         pottery etc have to be scientifically collected.  After the completion all documentation the burial
         goods will send to the museum.
         Trench excavation
             Trench  is  used  to  refer  to  small  or  sample  excavation  as  opposed  to open  area
         excavation. Even a large area excavation is only a sample of archaeological landscape and so is
         really a large trench. Trial trenches or trial pits or sondages are also the sampling excavation of
         the  sites.  They  are  often  small  square  trenches  (1m  x  1m)  in  order  to  recognize  the
         archaeological potentials of the site.
         Sieving
             Sieving is the most important part of excavations. This method, also known as screening
         or  sifting,  used  to  recover  quantifiable  data  from  excavations.  The  cultural  materials
         meticulously  recover  through  sieving  and  record  its  context  properly.    Prior  to  the  New
         Archaeology of the 1960s, sieving was not widely practiced and usually was restricted to the
         use of coarse mesh sieves for the recovery of small artifacts such as coins and beads. However,
         presently the archaeologists collect and document all artifacts, whether it is small or big, from
         the archaeological sites.
         Stripping
             Stripping is not often advisable in archaeological excavation. It involves the removal of
         topsoil accumulations. It is often carried out after a series of excavations that had taken place in
         various parts of the site. The removal, as efficiently as possible, of all above the surface those
         considered archaeologically not significant. For instance, in an urban context, this may involves
         removing the remains of recently demolished concrete building. This method is employed in
         contract archaeological work when the time factor is short.
         Stratigraphy and Law of superposition
             Stratigraphy  is  the  analysis  and  interpretation  of  depositional  layers  or  strata  in
         excavated  area.  In  archaeology,  stratigraphy  involves  a  careful  consideration  of  the
         characteristics of individual soil layers in order to understand how these layers relate to one
         another. As we learned in the previous chapter, there are geological strata and archaeological
         strata. The relation between the top most humus layer and natural layer in archaeological site
         explains the continuity or rupture, and changes occurred in the site during the past.
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             Edward  Harris  strongly  advocates  that  archaeological  stratigraphy    differ  from
         geological stratigraphy. There are certain basic laws and notions that are followed in identifying
         the  archaeological  stratigraphy.  They  are Law  of Superimposition,  Original  Horizontality,
         Original Continuity and Stratigraphical Succession.
         The Law of Superposition is of first importance in the interpretation of the stratification. It
         assumes that the strata and features are found in a position similar to that of their original
         deposition.
             “In a series of layers and interfacial features, as originally created, the upper units of
             stratification are younger and the lower are older, for each must have been deposited on,
             or created by the removal of, a pre-existing mass of archaeological stratification”.
         The Law of Superposition is a statement about the depositional order between any two strata.
         Since it only relates to any two units of stratification, it can make no declaration about the
         detailed position of strata in the stratigraphic sequence of a site. The law is simply a statement
         about the physical relationships of superimposed deposits, i.e. one lies on top of or underneath
         another,  and  is  therefore  later  or  earlier.  By  recording  superpositional  relationships,  the
         archaeologist  amasses  a  body  of  data,  which  will  be  of  assistance  in  determining  the
         stratigraphic sequence of the site.
         Law of Original Horizontality
             The Law of Original Horizontality assumes that strata, when forming, will tend towards
         the horizontal. This is determined by natural forces, such as gravity, and results in one deposit
         succeeding the other in a horizontal order of superposition. This law was originally applied to
         deposits formed by sedimentary processes under water, but may be used for dry-land deposits. It
         is defined for archaeological purposes in this way:
             “Any archaeological layer deposited in an unconsolidated form will tend towards a
             horizontal position. Strata which are found with tilted surfaces were originally deposited
             that way, or lie in conformity with the contours of a preexisting basin of deposition.”
         Law of Original Continuity
         The Law of Original Continuity is based on the limited topographical extent of a deposit or an
         interfacial feature.
             “Any  archaeological  deposit,  as  originally  laid  down,  or  any  interfacial  feature,  as
             originally created, will be bounded by a basin of deposition, or may thin down to a
             feather-edge. Therefore, if any edge of a deposit or interfacial feature is exposed in a
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